One good thing MRNA vaccines is that they don't need chicken eggs to grow the vaccine materials; like so many of the old style vaccines.
Think of all the laying hens that were kept in captivity. One wonders about the conditions. Chicken farms can be notorious. I still eat eggs, however. I usually try and find eggs from "free range" chickens. They do cost a little more, but worth it.
Newer technologies for making vaccines seem to be more humane, as far as I can tell.